— 1980: As Spain returns to democracy, ETA kills nearly 100 people, making 1980 the deadliest year in the group’s violent campaign.

— 1983: Members of Spain’s security forces establish Anti-Terrorist Liberation Groups, or GAL, to fight ETA and undermine its supporters. Over the following four years, GAL killed some 30 people.

— 1986: Twelve Civil Guard officers die in Madrid and 50 more people are wounded in a car-bomb attack in Madrid blamed on the ETA.

— 1987: In ETA’s bloodiest attack, bombs in the parking lot of a shopping center in Barcelona kill 21 people and injure 45 more.

— 1989: ETA declares its first ceasefire and engages in peace talks in Algiers with the Spanish Socialist government. But the militant group breaks the negotiations by killing a Civil Guard officer. Central authorities begin the so-called dispersal policy that sends imprisoned militants to prisons scattered across Spain with the goal of weakening ETA’s support network.

— 1992: The militant group suffers a major blow with the arrest of most of its leaders in Southern France.

— 1996: Francisco Tomas y Valiente, former president of Spain’s Constitutional Court, shot and killed at the Autonomous University of Madrid.

— 1997: Jose Ortega Lara, a Spanish prison worker, regains freedom after 532 days of kidnapping, the longest in ETA’s history. Shortly after, the organization kidnaps Miguel Angel Blanco, a young conservative councilor in the town of Ermua, and kills him after the government fails to meet the 48-hour deadline for transferring all ETA militants in custody to prisons in the Basque Country. The widespread protests in the wake of Blanco’s killing are considered a tipping point in the opposition to ETA both in and outside the Basque region.

— 1998: A new ETA truce before a regional election ends the following year after a failed dialogue with the conservative government of Jose Maria Aznar.

— 2002: Ternera goes into hiding after Spain’s Supreme Court summons him for his alleged involvement in a bomb attack in the barracks of the Civil Guard in Zaragoza that killed 11 people, including six minors.

— 2006: Ternera is one of the negotiators to meet with Spanish government envoys for talks to try to end the group’s activities. A third ceasefire is declared while Basque politicians hold secret peace negotiations involving the future of imprisoned Basque militants. ETA breaks the truce with a car filled with bombs exploding in the parking lot of the Madrid airport, killing two Ecuadorian citizens.

— 2010: A French police officer, Jean-Serge Nerin, is shot dead near Paris by militants fleeing after a car robbery, becoming ETA’s last fatal victim.

— 2011: An international peace conference in San Sebastian calls for ETA to declare a “definitive cease of its armed activity. On Oct. 20 the group declares the “definitive end” to its terrorism. Spanish officials say ETA is believed to have fewer than 50 members.

— 2017: ETA declares itself officially disarmed after handing over to French authorities dozens of weapons, ammunition and explosives. Spanish authorities demand for ETA to disband.

— 2018: In a letter to a Spanish newspaper published May 2, ETA says it has “dissolved all its structures.” In a recording released on May 3, Ternera’s voice is identified as one of the two ETA members who read a statement announcing the group’s dismantling. The announcement comes less than two weeks after the group offered an unprecedented apology that victims, their relatives, the Spanish and Basque governments say is too late and insincere.

— 2019: Ternera is arrested in Sallanches, a town of 16,000 in the eastern French Alps.